Demi Lovato's mum reveals abusive first husband cut off one of her fingers

Opens up about finding strength after overcoming domestic violence in new memoir.

Demi Lovato's mum, Dianna De La Garza, has opened up about the terrifying details of her abusive first marriage.

In her new memoir, Falling with Wings: A Mother's Story, De La Garza, 55, writes about surviving domestic violence at the hands of her first husband, Patrick Lovato, whom she wed in 1984.

After welcoming their first daughter, Dallas, in 1988, De La Garza reveals Patrick's substance abuse intensified and he struggled to find employment. She recalled a violent episode where he slammed a door so hard on her hand that she ended up losing a finger.

Despite living in terror, she said she stayed with him after learning she was pregnant again, this time with daughter Demi, born in 1992. Finally, when Demi was just 18- months-old, De La Garza fled the relationship.

Demi Lovato and Dianna De La Garza. Images: Getty, Instagram

"I thought I could change him, and I think victims of domestic abuse often feel the same way. You’re not always going to be able to change someone, no matter how much you want to," said De La Garza. "There may come a point where your love for that person may not be enough to keep you safe."

She said it was the only choice, for the safety of her daughters. "When I realized they were not safe anymore, no matter how much I loved this person and wanted things to change, I knew I had to get out," she says.

"I didn’t know how to leave, and I didn’t have any money," she added, revealing that she found help at a local women's shelter. "I would call them every day and talk to them, trying to gain the courage. I would ask them questions like, 'Am I doing the right thing by splitting up my family?'"

It's been 25 years since that turbulent time, but it has not been an easy road. De La Garza shared that she entered a treatment center in 2011 for PTSD, depression, anxiety, anorexia and Xanax addiction, one year after Demi was treated at the same facility to manage bipolar disorder, bulimia and self-harm.

De La Garza said that getting help allowed her to process years of buried pain.

"There were a lot of memories I had of that situation that I had pushed back in my memory, and something that is helpful is I did process through a lot of that incident when I was in a treatment center," she said.